OMG- step mom fucks my boyfriend .. how could she!?!

I brought my new boyfriend home with me, actually we had planned a cozy evening in front of the TV, but my stepmother had an eye on him right away. I'm just getting something to drink from the kitchen, because I catch my friend standing behind my stepmother and fucking her doggy! OMG how could you .... I was really shocked, I really wouldn't have thought that, but somehow it made me damn horny too ... That's how it all started. I really can't believe what happened there ...